The International Surface Pressure Databank

Submitted by gilbert.p.comp…
on Thu, 05/19/2011 - 16:31

The International Surface Pressure Databank (ISPD, Cram et al. 2015) is the world's largest collection of pressure observations. It has been developed by extracting observations from established international archives of meteorological variables and by combining these with observations made available through additional international cooperation with data recovery facilitated by the Atmospheric Circulation Reconstructions over the Earth (ACRE) Initiative and the other contributing organizations. The ISPD is assembled under the auspices of the GCOSWorking Group on Surface Pressure and the GCOS/WCRP Working Group on Observational Data Sets for Reanalysis by NOAA Earth System Research Laboratory (ESRL), NOAA's National Centers for Environmental Information (NCEI), and the University of Colorado's Cooperative Institute for Research in Environmental Sciences (CIRES).

The ISPD consists of three components: station observations, marine observations, and tropical cyclone best track pressure reports.

The station component is a blend of many national and international collections, with the largest contributor being surface and sea level pressure observations from the International Surface Database (ISD, Lott et al., 2008). Procedures for blending the station component are described at Yin et al. (2008).

The marine component consists of the available version of the International Comprehensive Ocean Atmosphere Data Set (ICOADS, Worley et al., 2005). In some ISPD versions, ICOADS Auxiliary data, ACRE recovered expeditions, and Oldweather.org data are also used.

The tropical cyclone component comes from the available version of the International Best Track Archive for Climate Stewardship (IBTrACS, Knapp et al., 2010). In the absence of a central pressure estimate, IBTrACS wind estimates are converted to pressure using an empirical gradient wind equation (Compo et al. 2011).

Version 4 (1722-2012)

Version 4 of the International Surface Pressure Databank has been merged.

NOAA's National Climatic Data Center has merged the station component using the ASCII exchange format v1.1. The marine component comes mainly from ICOADS version 2.5. The tropical cyclone component comes from IBTrACS V03r06.

NOAA's National Climatic Data Center has merged the station component using the ASCII exchange format v1.1. The marine component comes from ICOADS version 2.5. The tropical cyclone component comes from IBTrACS V03r03. ISPDv3 is being used in the century long reanalysis ERA-20C generated by ERA-CLIM, by the century long reanalysis being generated by JMA/MRI, and by NOAA/CIRES in 20CR version 2c.

Citation: Compo, G. P., et al. 2015. The International Surface Pressure Databank version 3. Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory. http://dx.doi.org/10.5065/D6D50K29. Accessed § dd mmm yyyy.§Please fill in the "Accessed" date with the day, month, and year (e.g. - 5 Aug 2011) you last accessed the data from the NCAR Research Data Archive.

For the period 1871-2011, Version 2 includes metadata information from the quality control system of the 20th Century Reanalysis Project. These so-called "feedback" records include the difference between the final analysis and each observation, the estimated uncertainty in the observation, and other quality information.

Citation: Compo, G. P., et al. 2010. International Surface Pressure Databank (ISPDv2). Research Data Archive at the National Center for Atmospheric Research, Computational and Information Systems Laboratory. http://dx.doi.org/10.5065/D6SQ8XDW. Accessed§ dd mmm yyyy.§Please fill in the "Accessed" date with the day, month, and year (e.g. - 5 Aug 2011) you last accessed the data from the NCAR Research Data Archive.

Future Additions

At http://badc.nerc.ac.uk/browse/badc/corral/images/metobs there any many useful links to information about known observations and their recovery status. The site has links to scanned images of hard copy meteorological observations held by the National Meteorological Archive of the UK Met Office that have been imaged to date. It also has an EXCEL file containing the status of all of the historical weather data (whether hard copy, scanned or digitised) being recovered, imaged, and digitised by the international ACRE community and international organisations projects and researchers linked to the Initiative for the ISPD. Additionally, the site has annual global maps showing terrestrial weather data distribution and their status.

The 20th Century Reanalysis Project used resources of the National Energy Research Scientific Computing Center and of the Oak Ridge Leadership Computing Facility at Oak Ridge National Laboratory, which are supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 and Contract No. DE-AC05-00OR22725, respectively. Support for the 20th Century Reanalysis Project dataset is provided by the U.S. Department of Energy, Office of Science Innovative and Novel Computational Impact on Theory and Experiment (DOE INCITE) program, and Office of Biological and Environmental Research (BER), and by the National Oceanic and Atmospheric Administration Climate Program Office.

Checking the map of the V4, the deepest in time we could expect to do a decent continuous North Atlantic Climate reanalysis using ISPD alone would be 1828. At this moment 1800, seams to be a hard limit to do any reanalysis at all for Europe. Unfortunately, they appears to be very little weather data available before 1850 not yet uncovered that could significantly improve this situation.
I assume the 20CR version 2C is using a database close to the version 4. In consequence, the 1871 spatial coverage will be significantly extended compared to version 2. For 1850, the reanalysis will be comparable to the reanalysis for 1871 of the version 2.

Dear Yvan,
As presented at the recent ACRE workshop in Toronto (proceedings will be online soon),
the 20CRv2c currently being generated is using ISPDv3 not version 4, which is still being merged. You can access annual maps of the version 3 station component at http://www.esrl.noaa.gov/psd/data/ISPD/ . Note that these are not quite the version 3.2.9 that 20CRv2c is using, which has additional coverage over New Zealand, for example.
Even so, the 1871 coverage is a substantial improvement over ISPDv2 used in 20CRv2.
As to coverage before 1828, our ACRE colleagues continue to uncover new sources, so I would not rule out additional stations being digitized for that period.

Thank's for the prompt answer.
Actually, I did notice that ISPDv4 map did not match with Phil Brohan visualisation of 20CR version 2C, after posting my comment.
I did also notice that many potential sites on the ISPD 2.2.4 map are not yet included in the version 4.
I assume the 20CR version 3 will be able to use version 4 or better.

Yvan,
Correct. We expect 20CRv3 to use ISPDv4 or later. Similarly, ISPDv4 will be available to ECMWF's CERA-20C, a coupled centential reanalysis, as well as to the JMA SOUSEI project, which is also undertaking a coupled centennial reanalysis. Both of these were also presented at the ACRE 7th workshop.
best wishes,

Hi,
When browsing the ISPD station map (http://www1.ncdc.noaa.gov/pub/data/ispd/add-station/v3.0/), I found a large gap in data between 1755 and 1767. I am under the impression that this is artifact and that data exist, but are not presented on these maps. Does I am right?

Dear Dr. Compo,
Thank you for your time of explaining for me. I'd like to consult you on some terminology.In your paper"The Twentieth Century Reanalysis Project", a minimum-error estimate of the 'true state' can be represented by the analysis ensemble mean(x¬a), page 6,in the bottom left corner,the paper also mentioned "the ensemble-mean analysis"(Hx¬a), page 8,in the bottom right corner. In the file Description of column data in ASCII format there is a variable ——"Ensemble mean analysis pressure". What are the differences between the analysis ensemble mean(x¬a),the ensemble-mean analysis(Hx¬a) and "Ensemble mean analysis pressure"? Thank you again for your time on this matter. Xiaoxiao

Dear Xiaoxiao,
"H" is the operator which interpolates the analysis vector to the observation time and location. In this case, it is interpolating pressure from the model grid to the observation location and time. The xa you are referring to is the mean of 56 fields or vectors. Hxa is the mean of 56 scalars. Please let me know if I can clarify further.
best wishes,
gil

Dear Xiaoxiao,
If you are interested, the individual members of the analysis fields from 20CR can be obtained at
portal.nersc.gov
The individual ensemble mean values of Hxa can be obtained from NCAR in the ISPD v2
http://rda.ucar.edu/datasets/ds132.0/
either in text files (see documentation http://rda.ucar.edu/datasets/ds132.0/docs/h5ftotxt.pdf )
or in HDF5 files (see documentation http://rda.ucar.edu/datasets/ds132.0/docs/International_Surface_Pressure_Data_Bank_format_v10.11.pdf)
Please reply if you need any further assistance.
best wishes,
gil

Dear Anonymous,
Yes, you are correct.
TYPE 183 and TYPE 180 ： relative to mean sea level TYPE 181："Observed Sea Level Press" is corrected and “Observed Surface Pressure” is not corrected . So, the 3 types are all relative to mean sea level except “Observed Surface Pressure” in type 181 .
May I suggest obtaining a login at this site? You can post comments with usually faster responses this way.
Please let us know if we can be more help.
best wishes,
gil compo

Dear professor,
May I ask two questions ?
On this page:http://rda.ucar.edu/datasets/ds132.0/index.html?hash=!access#!docs I found two documentations ("h5ftotxt.doc "and" International_Surface_Pressure_Data_Bank_format_v10.11.doc") contained the following information:
h5ftotxt.doc(for ASCII format )：
Observed Pressure
Float 8 8.2F
International_Surface_Pressure_Data_Bank_format_v10.11.doc(for HDF-5 format)：
1. Observed Sea Level Pressure
The atmospheric sea level pressure observation (hectopascals)
4. Observed Surface Pressure
The atmospheric surface pressure observation at the indicated elevation (hectopascals)
Elevation The elevation of a geophysical point observation relative to Mean Sea Level (meters)
My first question is :
Are "Observed Sea Level Pressure" and "Observed Surface Pressure" mentioned in the second file for HDF-5 format both included in the “Observed Pressure” mentioned in the first file for ASCII format, which can be distinguished according to the NCEP Type ?
The second question is :
The "Observed Surface Pressure" mentioned in the second file for HDF-5 format means "the atmospheric surface pressure observation at the indicated elevation",dose this suggests that the observed surface pressure data have been normalised to sea level (these data have been reduced to sea level) since the Elevation is relative to Mean Sea Level ?
Thank you for your kind consideration of the questions. It would be much appreciated if you can reply me about this.
Best wishes!
Sincerely yours,
Xiaoxiao Zhang

Dear Xiaoxiao,
Note that if you are seeing an NCEP type code of 183, this is a _station_ for which the ISPD only has a sea level pressure report. In no case is the column for Observed Surface Pressure reduced to sea level. It will be missing for stations that are of type 183. For stations of type 181, you may get both the Observed Surface Pressure and the Observed Sea Level Pressure.
In the ASCII file you are referring to, when a station has reported both surface and sea level pressure, it will coded as type 181 and both reports will be included.
Please let us know of any additional question.
best wishes,
gil compo

Dear Asia,
There are many such sites. It depends on what you mean by "latest surface and upper air chart".
Numerical Weather Prediction combines the available observations ("actual data") with a short term forecast to form the so-called "analysis".
One site with such products is the NOAA Earth System Research Laboratory Physical Sciences Division Map Room http://www.esrl.noaa.gov/psd/map/ . See, e.g., the Current Weather page at http://www.esrl.noaa.gov/psd/map/wx/current.shtml
Many products target a particular region. What is your region of interest?
The Unisys Weather Page has many useful maps for the United States http://www.weather.unisys.com/index.php
ECMWF has many useful maps. See http://www.ecmwf.int/products/forecasts/d/charts.
In general, this is a site for constructing analyses in retrospect, or "reanalysis".
Please let me know if I can be of more help.
best wishes,
gil compo

What you are seeing is the result of having used a T62 resolution spectral model to represent the orography of the earth in the 20th Century Reanalysis.

The pressure observations were adjusted to be consistent with the surface elevation of the assimilating NCEP model. Because of the long time period and many ensemble members, the resolution of the model was lower than one would prefer. This resolution is about 2degrees latitude by 2degree longitude. The spectral transformation will produce elevations in some reasons that have the sort of difference you are seeing from the true elevation.

Note that the ISPD record preserves the original elevation and value (or values if both station and sea level pressure were reported), as well as providing the value as modified to be consistent with the assimilating model's orography.

Bonjour,
Using data from your ISPD, I saw that, for some observed Pressures, the gap between the observation and the modified value can sometimes be huge. For example, one can read that an observation for the station of Biarritz, along the Atlantic sea shore, Souwestern France, for which elevation = 0m, Pobs = 1009.0hPa and the modified one = 947.0hPa with an error of 1.6hPa.
But, at the end of the line, the modified elevation is then 531m.
How could one explain these different values and such important discrepancies?
Many thanks,
Michel

I'm glad you are finding the 20th Century Reanalysis project (20CR) data useful. Thank you for the kind words.

I apologize for the confusion on what was assimilated. No wind data were ever assimilated from any platform. Only pressure data were assimilated.

The web page you mentionhttp://www.esrl.noaa.gov/psd/data/ISPD/v2.0/
is showing only locations of the station component of the ISPDv2: these station pressure or sea level pressure from stations were available for assimilation. It does not refer to the ships used (the marine component of ISPD) in any way. I apologize for the confusion.

ISPD version 2 described above was used in 20CR.

You can access all of observations used in 20CR, including the specific ICOADS ship pressure observations and their associated feedback information, fromhttp://rda.ucar.edu/datasets/ds132.0/

From the Compo et al (2011) http://dx.doi.org/10.1002/qj.776 paper Section 4 page 7 describes the precise data that were used, including the specific ICOADS version numbers as a function of year.

Dear Dr. Compo,
I'm a French researcher working at CNRS in La Rochelle University in the field of coastal oceanography. I'm presently using the 20CR reanalysis to investigate long-term variability of wind-waves and storm surges. My preliminary results are are very promising and by the way, I would like to congratulate you and thank you for the outstanding work that you did with your team.
In order to evaluate the time evolution of the acuracy of SLP and winds, I've planned to make a comparison between 20CR and data derived from Vonluntary Observing Ships taken from the ICOADS. Nevertheless, I was not able to understand from your 2011 paper if this data was assimilated in the 20CR reanalysis. Based on this webpage:
http://www.esrl.noaa.gov/psd/data/ISPD/v2.0/
I would conclude that it is not the case but I would be very grateful if you could confirm me. Thank you by advance and best regards,
Xavier Bertin

Version 2 of the ISPD can be obtained courtesy of Data Support Section of the Computational and Information Systems Laboratory at the National Center for Atmospheric Research from http://rda.ucar.edu/datasets/ds132.0/

Dear David,
This is curious, I would like to look into it further. But, first,
from the HURDAT site http://www.aoml.noaa.gov/hrd/hurdat/easyread-2012.html , I only see 2 storms during the 10-14 September period, not three:
Storm NOT NAMED is number 4 of the year 1928
Storm NOT NAMED is number 5 of the year 1928
Would you indicate what is the third system you are thinking of? Perhaps the third did not make it into HURDAT?
Thanks in advance,
Gil Compo

I have a question. I just ran across this link, which explains why some storms (particularly the historic ones landfall-wise) within Atlantic HURDAT seem to be depicted with the correct strength within the 20th century reanalysis pressure maps. The question is, if IBTrACS is used, which contains the Atlantic HURDAT, then why do some tropical storms and hurricanes appear to be missing? In particular, during the September 10-14, 1928 time frame, there are 3 tropical cyclones in existence between Florida, Bermuda, and the West Indes. However, the only tropical cyclone which appears on the pressure maps is the Great Miami Hurricane, which hit Florida on September 18. Why would two of the TCs not show up, when they showed up well in conventional data in real-time as well as HURDAT? See the October 1926 Monthly Weather Review article around page 411 for the conventional maps of the pressure pattern. Curious.